Electric and stepless structure for adjusting height of desktop

ABSTRACT

An electric structure is designed to adjust the desktop height level of a desk and is formed of a base frame on which two elevation seats are mounted. A desktop is fastened with the elevation seats such that the desktop is moved up and down along with the elevation seats. A pivoting rod is pivoted between the two elevation seats and is provided at two ends thereof with a gear which is engaged with one of two racks mounted on the base frame. The pivoting rod is driven to turn by a motor which is mounted under the desktop and is capable of turning forward or in reverse, so as to enable the desktop to rise or descend.

FIELD OF THE INVENTION

[0001] The present invention relates generally to a desk, and more particularly to an electric and stepless structure for adjusting height of the top of the desk.

BACKGROUND OF THE INVENTION

[0002] Certain conventional desks are provided with means to adjust the height of the top of the desks to suit the specific needs of a user of the desk. However, the adjustment of the height of the top of such conventional desks is done manually. The manual adjustment of the desktop is not an easy chore for a physically-handicapped person. In addition, the conventional means for the desktop adjustment is limited to a few steps. As a result, it is often difficult for a desk user to do a fine adjustment enabling the desktop to be located at an optimal height level.

SUMMARY OF THE INVENTION

[0003] The primary objective of the present invention is to provide an electrically-operated structure for adjusting the desktop of a desk in such a way that the desktop is located at an optimal height level in relation to a user of the desk.

[0004] The electrically-operated structure of the present invention comprises a base frame which is securely rested on a surface and is provided in two sides thereof with a rack extending longitudinally. The base frame is further provided with two elevation seats opposite to each other. A desktop is connected with the two elevation seats such that the desktop ascends and descends along with the two elevation seats. The desktop is pivoted at both ends thereof to the two elevation seats by means of a pivoting rod which is provided at both ends with a gear engaging the rack. A motor is fastened to the underside of the desktop for driving the pivoting rod.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005]FIG. 1 shows a perspective view of a preferred embodiment of the present invention.

[0006]FIG. 2 shows a front view of the preferred embodiment of the present invention.

[0007]FIG. 3 shows a left view of the preferred embodiment of the present invention.

[0008]FIG. 4 shows a top view of the preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0009] As shown in all drawings provided herewith, an electric and stepless structure of the present invention comprises component parts which are described hereinafter.

[0010] A base frame 10 is formed of two support feets 11 parallel to each other, two back columns 12 extending uprightly from the rear ends of the two support feets 11, and a back wall 13 fastened between the two back columns 12 which are rectangular tubes of a metal material. The rectangular tubes are provided in the front tube surface with a long slot hole 14 extending along the longitudinal direction thereof. The long slot hole 14 is provided in two sides with a clamp board 15 curving inwards, as shown in FIG. 4. The two back columns 12 are provided in the inner side portion of the front tube surface thereof with a rack 16 extending along the longitudinal direction thereof. The rack 16 of the preferred embodiment of the present invention is formed of a number of cross grooves 17. Both upper end and lower end of the rack 16 are kept a distance away from the top end and the bottom end of the back columns 12.

[0011] Two elevation seats 20 are fastened with the front sides of the two back columns 12 of the base frame 10 such that the two elevation seats 20 are opposite to each other. Each elevation seat 20 has a side board 21 whose back side is inserted into the back column 12 via the long slot hole 14 of the back column 12 such that the back side is held by the two clamp boards 15 of two sides of the long slot hole 14. The side board 21 located in the interior of the back column 12 is provided in two sides with a bearing 22 pivoted therewith such that the periphery of the bearing 22 presses against the inner wall of the back column 12, thereby enabling the elevation seat 20 to slide stably along the longitudinal direction of the back column 12. The left elevation seat 20 is provided in the inner side of the side board 21 with a motor seat board 23 extending therefrom.

[0012] A desktop 30 of a rectangular construction is fastened at left side and right side with the tops of the two elevation seats 20 such that the desktop 30 is moved up and down along with the elevation seats 20. The desktop 30 of the preferred embodiment of the present invention is horizontally set up. The desktop may be slanted or joined with the elevation seats by means of a movable structure which is often used in a draftsperson's desk. The desktop may be provided with drawers fastened thereunder, or a keyboard slide seat, etc.

[0013] A pivoting rod 40 is pivotally fastened at both ends with rear sides of the side board 21 of the two elevation seats 20 and is provided at both ends with a gear 41 fastened therewith. These two gears 41 are engaged with the two racks 16 of the two back columns 12. The pivoting rod 40 is further provided with a worm gear 42 fastened therewith in proximity of the left end of the pivoting rod 40.

[0014] An electric mechanism 50 is formed of a motor 51, which is mounted on the seat board 23 of the left elevation seat 20. The motor 51 is connected with a gear box 52 for magnification deceleration. The gear box 52 is provided at the front end with an output shaft 53 perpendicular to the pivoting rod 40. The output shaft 53 is provided at the tail end with a worm rod 54 fastened therewith such that the worm rod 54 is meshed with the worm gear 42 of the pivoting rod 40.

[0015] In the process of adjusting the desktop height level, the motor is started to turn forward or in reverse. The pivoting rod 40 is then driven to turn by the worm rod 54 and the worm gear 42 mechanisms. As a result, the mechanism of the gear 41 and the rack 16 enables the pivoting rod 40 to rise or descend horizontally so as to force the elevation seats 20 and the desktop 30 to move up or down. The present invention can be easily operated by a patient, a handicapped person, or a person on wheelchair. The gear 41 can be located at any position of the rack 16 to facilitate the fine adjustment of the desktop height level.

[0016] The motor 51 is mounted on the inner side of one of the two elevation seats 20. The motor may be fastened to the underside of the desktop. The worm gear of the pivoting rod must be disposed in a corresponding position. The worm rod 54 of the output shaft 53 of the motor 51 and the worm gear 42 of the pivoting rod 40 may be interchanged. The desktop 30 will not sink after adjustment in view of the fact that the worm rod and the worm gear are securely engaged even if the mechanism of the worm rod and the worm gear is stopped. The worm rod and the worm gear may not be mounted on the motor output shaft and the pivoting rod. For example, the motor output shaft may be parallel to the pivoting rod such that the gear is engaged with the pivoting rod. In the meantime, the worm rod and the worm gear are disposed in the gear box for magnification deceleration. 

What is claimed is:
 1. An electric and stepless structure for adjusting height level of the desktop of a desk, said structure comprising: a base frame rested stably on a surface and provided in two sides thereof with a rack extending longitudinally; two elevation seats slidably mounted in two sides of said base frame; a desktop fastened at two sides with said elevation seats; a pivoting rod pivoted horizontally between said two elevation seats and located in rear side of underside of said desktop, said pivoting rod provided at two ends with a gear which is engaged with said rack of said base frame; and an electric mechanism comprising a motor which is mounted under said desktop for driving said pivoting rod to turn.
 2. The structure as defined in claim 1, wherein said motor drives said pivoting rod via a set of a worm rod and a worm gear.
 3. The structure as defined in claim 2, wherein said motor has an output shaft perpendicular to said pivoting rod; wherein said worm rod and said worm gear are respectively mounted on said output shaft and said pivoting rod.
 4. The structure as defined in claim 3, wherein said worm rod and said worm gear are located in proximity of one end of said pivoting rod; wherein said motor is mounted in an inner side of said elevation seat corresponding in location to one side of the set of the worm rod and the worm gear, said motor being located under said desktop.
 5. The structure as defined in claim 1, wherein said base frame comprises two support feet in contact with the surface, two back columns extending uprightly from rear ends of said two support feet, and a back board fastened between said two back columns; wherein said two racks are mounted on said two back columns.
 6. The structure as defined in claim 5, wherein said back columns are rectangular tubes, with a front side tube surface having a long slot hole extending along the longitudinal direction thereof, said long slot hole being provided with a clamp board curving inward; wherein said elevation seats have a side board whose rear side is inserted into said back column via said long slot hole and is held by said two clamp boards, said side board located in an interior of said back column being provided in two sides thereof with a bearing pivoted therewith such that periphery of said bearing presses against inner wall of said back column.
 7. The structure as defined in claim 6, wherein said back column is provided in a front surface of the tube wall thereof with a plurality of cross grooves which form said rack. 